Traditionally an ophthalmic lens, such as a contact lens or an intraocular lens provided a predetermined optical quality. A contact lens, for example, can provide one or more of: vision correcting functionality; cosmetic enhancement; and therapeutic effects; but only a set of vision correction functions. Each function is provided by a physical characteristic of the lens. Basically a design incorporating a refractive quality into a lens provides vision corrective functionality. A pigment incorporated into the lens can provide a cosmetic enhancement. An active agent incorporated into a lens can provide a therapeutic functionality.
To date optical quality in an ophthalmic lens has been designed into the physical characteristic of the lens. Generally, an optical design has been determined and then imparted into the lens during fabrication of the lens, such as, for example through cast molding, or lathing. The optical qualities of the lens have remained static once the lens has been formed.
However, wearers may at times find it beneficial to have more than one function for a biomedical device worn in their eye; for example, it would be advantageous for an ophthalmic lens to have multiple focal powers available to them in order to provide sight accommodation. Other functionalities may also be useful. Unlike spectacle wearers, who can change spectacles to change an optical functionality, contact wearers or those with intraocular lenses have not been able to change the functional characteristics of their vision correction without significant effort.